There are some amazing ideas, I really like how you've added a reference image to each one to give people an idea of how it would work plus a different concept behind them. I have to say how much I love the Moon Base idea, however, I think that the idea of a moon base is quite bland and there isn't enough to spice it up to make it an FFA map, FFA maps are pretty huge and have a lot in them, I personally believe that a Moon Base wouldn't work with this type of game mode. I think it's best suited to Survival Games because of the map size.
Suspension is a unique one, I think it should also be changed to fit Block Wars due to the double sided nature of the map, how there is only one direction you can really go in. Maybe make the wires holding the bridge accessible to add more ways to attack. Because Block Wars maps have this way where if there's a wall in the way you either go around or through, this map could change that because of the short width of the map. It's go through or go over.
I think that Cube City or some form of City would make a great Assassination map, being that Assassins have shops and those shops tend to have large buildings with logos on them so that they're noticeable. You could make specific Skyscrapers have the shop logos on them.
Anywho; fantastic suggestions. I really want to see many of these make their way onto the server. :)